J. Blass at Cornell has shown that the activity of three thiamine- dependent enzymes--transketolase, alphaketoglutarate dehydrogenase, and pyruvate dehydrogenase--are decreased in two dementias, Wernicke-Korsakoff Syndrome and Alzheimer's disease. In general, this decrease occurs in body tissues not directly affected by the disease process; this suggests that inactivation of these enzymes is not simply an effect of the underlying pathology but may be intimately related to the cause of each disease, perhaps directly or perhaps as a predisposing factor. The goal of this project is to pursue this idea at the molecular level by cloning the gene for transketolase. A lambda gt11 library of possible clones has been screened using an antitransketolase antibody, but unfortunately this antibody was only able to pick out clones corresponding to transferrin. This collaborative project is therefore on hold until the Blass laboratory can produce a more specific antibody.